Exactly: "normal" and "simulated" should be indistinguishable - and often, for me having reg/green deficiency, that's the case. I'll often look to confirm that images truly are different before using them as examples.

Colour deficiencies vary, though, so even a simulation that works perfectly for some is not going to be a universal simulation.

These simulations are amazing in terms of illustrating to colour-capable people what we colour-deficient actually see: it's not black and white, to us the world is still bright, vivid, colourful. It's our normal and that mostly isn't a problem. But a bright red rose that's colourful and vivid to me, looks to my wife grey and faded.